There are times when Cognito makes a ton of sense (I wrote about some of them here[0]). There are other times when it doesn't.
What I keep wondering and asking is "why doesn't AWS invest more in Cognito?"[1]
0: https://fusionauth.io/blog/how-to-migrate-from-cognito#when-...
1: https://ciamweekly.substack.com/p/trends-in-ciam